Boston had 18 points, 10 rebounds and four blocks as the Gamecocks rallied from 10 points down to beat No. 15 UCLA 73-64 on Tuesday night.
The reigning AP Player of the Year had missed the second half in a win over Hampton on Sunday after a hard fall. She returned to the bench in that game with a walking boot on her right foot.
But Boston started and played 35 minutes against the Bruins (7-1) to help the Gamecocks (7-0) overcome a 31-21 deficit right before halftime to win their 17th straight over a ranked opponent.
"I think the trainers did a great job with my ankle so it's feeling pretty good," said Boston, the 6-foot-5 senior who posted her 65th career double-double and 32nd against a ranked opponent.
Georgia Tech transfer Kierra Fletcher had a double-double with 12 points and 10 rebounds while the 6-foot-7 Kamilla Cardoso added a season-high 16 points, nine rebounds and five of the Gamecocks' 15 blocked shots.
Gamecocks coach Dawn Staley didn't know for sure until a few hours before tipoff that Boston would be healthy enough to start. Staley said Boston woke up Monday feeling better and that progressed into Tuesday's pregame preparations.
The score was tied at 47 entering the fourth quarter. That's when the Gamecocks turned up their smothering defense, holding UCLA to just three field goals in the final 10 minutes.
"They were very disciplined in the fourth quarter with what they wanted to do," UCLA coach Cori Close said. "We couldn't stop that."
Zia Cooke's tiebreaking bucket with 5:37 left in the game put South Carolina up for good at 54-52. The Gamecocks led by as many as 10 points in the final minutes.
Early on, UCLA and Rice upped the pace and took things right into the heart of South Carolina's smothering defense to build a 10-point lead late in the second quarter.
South Carolina missed 11 straight shots during one stretch, including a sequence in which it had four consecutive chances from close.
The Gamecocks showed some life in the final minutes as Boston had two blocks and a basket to cut the margin to 31-27 at the break. UCLA missed its last seven shots of the quarter.
Staley said she simplified the offense in the second half, leading Fletcher to several made buckets and Boston and Cardoso to find space underneath the basket.
"We made it really hard on them," Staley said.